Ubiquitination is a dynamically reversible post-translational modification by incorporating 76 amino acids contained polyubiquitin peptide to proteins. The removal of ubiquitin by deubiquitylating enzymes (DUBs) counteracts the activity of ubiquitin ligases and is now considered to be equally significant for protein regulation. There are about 100 DUBs found in the human genome. It has been illustrated that DUBs are responsible for ubiquitin precursor processing, ubiquitin recycling, trimming of ubiquitin chains, and also make contributions to cell growth and differentiation, development, DNA damage, transcriptional regulation and chromatin remodeling. In the past few years, numerous DUBs have been found to be implicated in various diseases spanning oncology, hematology, neurodegeneration, and infectious diseases. DUBs have been considered as promising targets for drug development.